Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences, especially in ore deposits where sulfide-sulfate pair coprecipitates widely. However, in-situ S isotope determination of barite is challenging without natural matrix-matched reference material. In this study, we present two natural barite reference materials (1-YS and 294-YS) for in-situ sulfur isotopic analysis. Independent LA-MC-ICP-MS laboratories were utilized to test the δ³⁴S micron-scale homogeneity of 1-YS and 294-YS barites that have 2s repeatabilities of better than ±0.45‰ and ±0.41‰, respectively. Meanwhile, the in-situ analysis results are consistent with the results of the bulk analysis by GS-IRMS within uncertainty. The grand mean δ³⁴S values of 1-YS (13.37‰ ± 0.42‰, 2s) and 294-YS (14.38‰ ± 0.44‰, 2s) are the final recommended values obtained from four independent laboratories. All the results confirm the suitability of 1-YS and 294-YS barite used as calibration materials with respect to in-situ S isotopic analysis. Moreover, the new developed barite reference materials were used as matrix-matched standard to calibrate the barite samples from the Huayangchuan carbonatite-hosted U-polymetallic deposit (Qinling orogenic belt, western China) to obtain δ³⁴S values. Utilizing the temperature-dependent δ³⁴S fractionation of barite-pyrite pair, we calculate the formation temperature of barite (i.e., 506 to 537 ºC) and the δ³⁴S value of mineralizing fluid (i.e., -7.11‰ to -7.59‰) in the Huayangchuan deposit. The results indicate an involvement of sedimentary sulfur, presumably acting as a potential uranium source (e.g., upper crustal materials) for the giant Huayangchuan deposit.

Original sedimentary manganese (Mn) deposits and supergene Mn ores are important Mn resources in China. However, the geochemical information from Chinese supergene Mn ores is scarce, and the relationship between sedimentary Mn deposits and supergene Mn ores is ambiguous. In this study, we collected the original Mn-bearing dolomitic sandstones (ZK20-3 drillcore) and supergene Mn ores (Longmen Section) from eastern Hebei, North China for systematic petrographic, mineralogical and geochemical analyses. Our new data help us to figure out the transformation from original Mn-bearing deposits to supergene ores. The main minerals of original Mn-bearing dolomitic sandstones are quartz and feldspar, with minor muscovite, dolomite, rhodochrosite, ankerite, and kutnohorite. Supergene Mn-oxide ores only emerged in the middle part of the Longmen (LM) Section, and mainly contain quartz, pyrolusite, cryptomelane, todorokite and occasional dolomite. The possible transformation sequence of Mn minerals is: kutnohorite/rhodochrosite → pyrolusite (I) → cryptomelane (todorokite) → todorokite (cryptomelane) → pyrolusite (II). For Mn-oxide ores, Fe, Na and Si are enriched but Al, Ca, Mg and K are depleted with the enrichment of Mn. For original and supergene ores, the total rare earth element + ytterbium (∑REY) contents range from 105.68 × 10^-6 to 250.56 × 10^-6 and from 18.08 × 10^-6 to 176.60 × 10^-6, respectively. Original Mn ores have similar slightly LREE-enriched patterns, but the purer Mn-oxide ore shows a HREE-enriched pattern. In the middle part of the LM Section, positive Ce anomalies in Mn-oxide ores indicate the precipitation of Ce-bearing minerals. It implies the existence of geochemical barriers, which changed pH and Eh values due to the long-time influence of groundwater.

Mineral identification and discrimination play a significant role in geological study. Intelligent mineral discrimination based on deep learning has the advantages of automation, low cost, less time consuming and low error rate. In this article, characteristics of quartz, biotite and K-feldspar from granite thin sections under cross-polarized light were studied for mineral images intelligent classification by Inception-v3 deep learning convolutional neural network (CNN), and transfer learning method. Dynamic images from multi-angles were employed to enhance the accuracy and reproducibility in the process of mineral discrimination. Test results show that the average discrimination accuracies of quartz, biotite and K-feldspar are 100.00%, 96.88% and 90.63%. Results of this study prove the feasibility and reliability of the application of convolution neural network in mineral images classification. This study could have a significant impact in explorations of complicated mineral intelligent discrimination using deep learning methods and it will provide a new perspective for the development of more professional and practical mineral intelligent discrimination tools.

The Yangchuling porphyry W-Mo deposit (YPWD), located in the Jiangnan porphyry-skarn tungsten ore belt, is one of the most important and large-scale porphyry W-Mo deposits in South China. While previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling W-Mo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at ~150–144 Ma, their post emplacement history remains poorly understood, making their preservation status at depth uncertain. In this paper, new zircon and apatite (U-Th)/He and apatite fission track (ZHe, AHe and AFT, respectively) data of one hornfels and five intrusive rocks from a 1 000-meter borehole are presented. These, together with new inverse thermal history models and previous geochronological data, help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo deposit. In general, ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation, ranging from 133 to 73 Ma and 67 to 25 Ma, respectively. All four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2 ± 0.7 to 12.6 ± 0.5 μm. Thermal history modelling indicates that the Yangchuling ore district experienced slow, monotonic cooling since the Cretaceous. Age-depth relationships are interpreted as recording ~3.7 ± 0.8 km of Cretaceous-recent exhumation in response to regional extension throughout South China thought to have been driven by subduction retreat of the Paleo-Pacific Plate. Comparison of estimated net exhumation and previous metallogenic depth of ~4–5 km suggests that W-Mo ore bodies could still exist at depths of up to ~1.3 ± 0.8 km relative to Earth surface in the YPWD region. Preservation of the YPWD is attributed to the limited amount of regional denudation during the Late Cretaceous and Cenozoic.

The Chang 7 sandstone is characterized by complex micro-pore structures, strong heterogeneity, and differential fluid distribution. These characteristics result in low oil recovery. In this paper, various techniques, including high-pressure mercury intrusion, nuclear magnetic resonance, scanning electron microscope, thin section, and X-ray diffraction, are employed to quantitatively evaluate the occurrence characteristics and influencing factors of movable fluids in Chang 7 sandstone reservoirs from the Heshui Block with different fractal structures. Results show that the dominant sandstone type is feldspar lithic fragment sandstone. Chang 7 reservoir has been divided into three types (types I, II, and III) based on capillary pressure curves and pore structure parameters. These reservoirs are characterized by various fractal structures and different movable fluids distribution. Multiple possible factors affecting the movable fluid distribution are analyzed, including physical properties, pore structure, pore size distribution, mineral content, and heterogeneity. Movable fluid saturation is positively correlated with physical properties, weighted average pore-throat radius, median pore-throat radius, final residual mercury saturation, and maximum mercury withdrawal saturation. In contrast, it is negatively correlated with displacement pressure and has no obvious correlation with the sorting coefficient. Micron- and submicron-scale pores are beneficial to the movable fluid occurrence, while nano-scale pores are vice versa. The influence of mineral content on movable fluid occurrence varies with mineral types. Quartz is conducive to the movable fluid occurrence in submicron-scale pores, while carbonate cementation inhibits the movable fluid occurrence in submicron-scale pores. The inhibition of clay on the movable fluid occurrence is mainly reflected in submicron- and nano-scale pores and varies with clay mineral types. The influence of heterogeneity on the movable fluid occurrence is mainly reflected in submicron-scale pores. The occurrence models of movable fluid vary with reservoir types.

The widespread dolomite of the Sinian Dengying Formation in the Sichuan Basin (China) serves as one of the most important oil and gas reservoir rocks of the basin. Well WT1, as an exploration well, is recently drilled in the Kaijiang County, northeastern Sichuan Basin (SW China), and it drills through the Dengying Formation dolomite at the depth interval of 7 500–7 580 m. In this study, samples are systematically collected from the cores of that interval, followed by new analyses of carbon-oxygen isotope, major elements, trace elements, rare earth elements (REEs) and EPMA. The Dengying Formation dolomites of Well WT1 have δ¹³C values of 0.37‰ to 2.91‰ and δ¹⁸O values of -5.72‰ to -2.73‰, indicating that the dolomitization fluid is derived from contemporary seawater in the near-surface environment, rather than the burial environment. Based on the REE patterns of EPMA-based in-situ data, we recognized the seawater-sourced components, the mixed-sourced components and the terrigenous-sourced components, indicating the marine origin of the dolomite with detrital contamination and diagenetic alteration. Moreover, high Al, Th, and Zr contents indicate significant detrital contamination derived from clay and quartz minerals, and high Sr/Ba and Sr/Cu ratios imply a relatively dry depositional environment with extremely high seawater salinity, intensive evaporation, and strong influences of terrigenous sediment.

Gastropods, as one of the most common invertebrates in shallow marine environments, were heavily impacted by the Permian–Triassic mass extinction (PTME), with severe loss of diversity and remarkable dwarfism of body size. Here, we report a new gastropod fauna from the Permian‒Triassic carbonates of Zuodeng, Guangxi Province, South China. Five species belonging to five genera and two indeterminate taxa are identified. The Zuodeng fauna is dominated by Paleozoic holdover taxa, including Holopea teres, Protostylus sp., and Wannerispira shangganensis although most of them are found in the basal Triassic microbialites. Three gastropod communities have been recognized by cluster analysis. Further morphological analyses show that the changing pattern of disparity, with diversity decreasing from community Ⅱ to Ⅲ, fits the interior-reduction model. In addition, the morphospace of community in microbialites is higher than those in non-microbialite bearing beds at Zuodeng, shedding new light on the ecological role of microbialites during the Permian–Triassic environmental stress.

The Ediacaran Period records a significant turning point in the evolution of life on Earth, witnessing the rise to ecological dominance of macroscopic tissue-grade organisms. The Wenghui biota from the Doushantuo Formation of South China hosts abundant multicellular algal macrofossils and problematica, some of which might be closely related to taxa from classic Late Ediacaran assemblages from South Australia and the White Sea biota of Russia. However, a lack of well-resolved isotopic age estimates has hampered efforts to constrain the timing of appearance of the Wenghui biota, obfuscating its significance to our understanding of Ediacaran macroevolution in the aftermath of the Snowball Earth events. Here, we present the first SHRIMP zircon U-Pb dating results for samples obtained from a laminated tuff ash layer at the base of the Wenghui biota in the Doushantuo Formation, Jiangkou County, Tongren City, Guizhou Province, China. Our analyses yield an age of 595.4 ± 5.3 Ma for the first appearance of Wenghui biota, suggesting that its appearance postdated that of the Lantian and Weng'an biotas, but preceded that of the Miaohe biota. These newly obtained age proxies offer an independent test of previous isotopic estimates for the age of the Wenghui biota, providing new chronostratigraphic evidence to map the succession of Ediacaran fossil assemblages on the Yangtze Platform during the Doushantuo interval. These data suggest that the Lantian, Weng'an, Wenghui, and Miaohe biotas may record a sequence of biotic assemblages attesting to successive phases in the radiation of Ediacaran macroscopic organisms, particularly macroalgae.

Phosphorus (P) is the main limiting factor in eutrophication. Sediment P can be released decades after its accumulation. Lake restoration requires the reduction of internal sediment P loading. Although we tried to provide a comprehensive summary of the state-of-the-art sediment P control technologies, our analyses in this review are focused on the mechanisms, control effects, and application conditions of different in-situ technologies including physical control, chemical control, ecological remediation, and combined control technology. The design principles, feasibility, operation parameters, and pros & cons of these technologies are analyzed and compared. More efforts are needed to improve in-situ sediment P control technologies so as to enhance the interaction between materials and plant communities and promote the adsorption and fixation of active P in sediments. The control materials for internal sediment P loading need to be further studied in terms of their functional properties, pre-evaluation of the P control effect, and engineering applications.

The Tibetan Plateau has a large number of hot springs with varying temperatures and hydrochemistry, high elevation, and limited nitrogenous nutrition. Nitrogen-fixing bacteria (NFB) can fix N₂ to form ammonia and thus provide bioavailable nitrogen. However, there is limited knowledge about the distribution of NFB and its influencing factors in Tibetan hot springs. Here, we measured hydrochemical variables of the hot springs with a wide temperature range (32–77 ºC) in the Qucai and Daggyai geothermal zones on the Tibetan Plateau and investigated the composition of NFB using high-throughput sequencing of 16S rRNA and nifH genes. The Cl^-/SO₄^2- ratio in Qucai hot springs was higher than that in Daggyai, indicating that Qucai and Daggyai hot springs were more affected by the supply of liquid and gaseous phases, respectively. The NFB communities consisted predominantly of Nirtospirae, Chloroflexi, Deltaproteobacteria and an unidentified clade, with the last three acting as the main NFB with over 42% of the communities (the proportions are significantly larger than those found in hot springs of other geothermal regions). This demonstrates the uniqueness of NFB communities in Tibetan hot springs. NFB richness was limited by temperature in the studied Tibetan hot springs and was significantly lower than in low-elevation geothermal regions. The NFB community was predominantly affected by hydrochemistry, in contrast to the entire prokaryotic community, which was primarily influenced by temperature. This study expands our current understanding of NFB distribution and diversity as well as biogeochemical process in geothermal spring environments.

Previous works were mainly concentrated on long-term average runoff alterations, and extreme temperatures and watershed conditions are little analyzed. In this study, we collected gauged river flow and meteorological data time series from 1916 to 2015 and 1941 to 2015 across the contiguous United States (CONUS) for 188 catchments to investigate the temporal trends and spatial features of runoff changes at multi-time scales. We also analyzed the relationships between runoff changes and climatic factors. Median descriptive statistics and Budyko coupled climate elasticity methods were used to calculate runoff elasticity in each time scale. The original Mann-Kendall trend test was used to test their trend significance in four time-scale (11, 20, 40, and 60 a), respectively. The results show that the trend of runoff changes is more significant in high time scales; total changes are heterogeneous over CONUS. After the 1970s, increases of up to 27% decade^-1 were mainly concentrated in the mid-northern regions. Maximum temperature and catchment characteristics are vital factors for runoff alteration; runoff changes are independent of rainfall, and wet regions tend to have lower changes. These findings could help develop better regional water resource planning and management.

High-resolution, continuous Late Holocene lacustrine records are scarce in the Qaidam Basin, but is of especially important for our understanding the future climate variability in the western China. Here, we use grain size, element content and XRD-identified data from the Lake Hurleg in the eastern Qaidam Basin to present the Late Holocene climate variability, which have been temporally constrained using ²¹⁰Pb-, ¹³⁷Cs- and AMS ¹⁴C dating. Our records demonstrate that decreased precipitation climate occurred at ~800–1000 yr and ~1300–1800 yr intervals, and increased precipitation occurred at ~354–800 yr, ~1000–1300 yr and ~1800 yr to the present. The results show that the Qaidam Basin has undergone a process of warming and humidification since the Industrial Revolution, which is consistent with the meteorological records. The climate in the northeastern Qaidam Basin is dominated by the Asian Monsoon.

Groundwater is the main water supply source in the Tarim Basin in China. Endemic disease caused by high iodine (Ⅰ) groundwater in the Tarim Basin was reported previously. Therefore, it is crucial to systematically identify the distribution and genesis of groundwater Ⅰ. Based on hydrochemical analysis of 717 groundwater samples collected in 2015–2018, spatial distribution and hydrogeochemistry characteristic of high Ⅰ groundwater in different aquifers were analyzed. Results showed that groundwater Ⅰ ranged between < 10.00 and 4 000.00 μg/L (mean of 53.71 μg/L). High Ⅰ groundwater (Ⅰ > 100.00 μg/L) accounted for 7.25% of the total samples. Horizontally, groundwater Ⅰ significantly increased from recharge zone (RZ) to transition zone (TZ) and to evaporation zone (EZ). Vertically, groundwater in shallow confined aquifer (SCA) had the greatest Ⅰ concentration, followed by single-structure phreatic aquifer (SSPA), phreatic aquifer in confined groundwater area (PACGA), while groundwater in deep confined aquifer (DCA) generally had low Ⅰ concentration. Groundwater Ⅰ enrichment in SSPA was mainly affected by organic matter (OM) decomposition and that in SCA was mainly affected by evaporite mineral dissolution, OM decomposition under alkaline environment. While Ⅰ enrichment in groundwater of PACGA was restrained under neutral environment. Lacustrine sedimentary environment was crucial for Ⅰ enrichment in groundwater. Besides, fine-grained lithology of aquifer, smooth topographic slope, shallow buried depth of groundwater, weak alkaline and reducing environment, reductive dissolution of iron oxide/hydroxide minerals and OM decomposition were advantageous to Ⅰ enrichment in groundwater.

Climate change and economic development impact the population expansion and water shortage in the middle reaches of the Yangtze River Basin (MYRB), leading directly to drought aggravation-expansion and impacting agricultural production in the MYRB. Therefore, this study quantitatively evaluated agricultural drought vulnerability in the MYRB based on the variable fuzzy evaluation model (VFEM). The main conclusions are as follows: (1) The arable land in the MYRB gradually decreased between 2005 and 2020, whereas the forest cover decreased and then increased; (2) precipitation and evapotranspiration were the key factors affecting the agricultural drought vulnerability (e.g., weights of 0.24 and 0.21), whereas arable land density and gross domestic product (GDP) per capita played less significant roles; and (3) the agricultural drought vulnerability in the MYRB during 2005–2020 was mainly at level 3 and below, with higher drought vulnerability in the western and northern regions, which had a higher drought risk potential.

Enhanced silicate weathering (ESW) is a geoengineering method aimed at accelerating carbon dioxide (CO₂) removal (CDR) from atmosphere by increasing the weathering flux of silicate rocks and minerals. It has emerged as a promising strategy for CDR. Theoretical studies underscore ESW's substantial potential for CDR and its diverse benefits for crops when applied to croplands. However, the well-known significant discrepancies in silicate weathering rates between laboratory and field conditions introduce uncertainty in CDR through ESW. By compiling data from recent literature, we calculated and compared CDR efficiency (t CO₂ t_silicate^-1 ha^-1 y^-1) observed in mesocosm experiments and field trials. The findings indicate that CDR efficiencies in field trials are comparable to or exceeding that observed in mesocosm experiments by 1-3 orders of magnitude, particularly evident with wollastonite application. The hierarchy of CDR efficiency among silicates suitable for ESW is ranked as follows: olivine ≥ wollastonite > basalt > albite ≥ anorthite. We suggest the potential role of biota, especially fungi, in contributing to higher CDR efficiencies observed in field trials compared to mesocosm experiments. We further emphasize introducing fungi known for their effectiveness in silicate weathering could potentially enhance CDR efficiency through ESW in croplands. But before implementing fungal-facilitated ESW, three key questions need addressing: (ⅰ) How does the community of introduced fungi evolve over time? (ⅱ) What is the long-term trajectory of CDR efficiency following fungal introduction? and (ⅲ) Could fungal introduction lead to organic matter oxidation, resulting in elevated CO₂ emissions? These investigations are crucial for optimizing the efficiency and sustainability of fungal-facilitated ESW strategy.

Arid regions are vital components of Earth's land surface. Clarifying the area/boundary of arid region is crucial for comprehending area changes and potential mechanisms. However, the accuracy and applicability of arid region boundary delineated by different indices remain unclear. In this study, the annual precipitation (AP), humidity index (H), and aridity index (K) were calculated for delineating arid region of China using 106 meteorological stations during 1990–2019. The results suggest that AP and H can accurately delineate arid region, because they are consistent with the distribution of typical soil and vegetation in arid region, whereas K is not. Moreover, AP is the best index for delineating arid region in regions with limited meteorological data, especially in studying long-term patterns and mechanisms of area changes. The accuracy of delineating arid region using H is enhanced in regions with abundant meteorological data. Over the past 30 years, influenced by the increase of atmospheric moisture influx and precipitation, the area in arid region of northwestern China decreased by 70 × 10³–90 × 10³ km², resulting in the present area of approximately 1.55 × 10⁶ km². This study provides appropriate indices for delineating arid region, contributing to improving our knowledge of regional responses difference to climate change.

Fluid channeling caused by seal failure at the cement sheath-formation interface during fracturing is a severe problem in oil gas wells. In this study, a novel model was developed to evaluate interface sealing integrity. The model's accuracy was verified based on a self-developed interface seal evaluation device and an experiment. Subsequently, the interface seal under different formation conditions was investigated using this model. The theoretical calculation showed that for a cement sheath-carbonate formation interface, the channeling of acid-fracturing fluid caused interface seal failure and sustained casing pressure in the annulus space between the technical casing and formation. Mutual channeling between the fracturing sections occurred at the cement sheath-shale formation interface during fracturing. For a sandstone formation, the interface seal failure caused the channeling between a water-bearing formation and a sandstone formation. Aiming at different formation conditions, the mechanical properties requirements of Young's modulus and Poisson's ratio of cement sheath were proposed respectively to ensure its seal integrity. The proposed model and method can be used to evaluate and optimize sealing integrity during fracturing.

Mantle plumes and surface erosion and sediment deposition affect the modes of continental lithospheric rupturing in extensional tectonic settings, modulating the evolution of rifting margins. However, their relative contributions to the overall evolution of rifting margins and possible roles in the formation of microcontinent are still elusive. Here, we use coupled geodynamic and surface processes numerical modeling to assess the extent to which surface processes may determine the formation of microcontinent during lithospheric stretching in presence or absence of a mantle plume underneath. Our modeling results indicate that fast extension rates and hillslope (i.e., diffusion) erosion promote ridge jump events and therefore the formation of microcontinents. On the contrary, efficient fluvial erosion and far-reaching sediment transport (i.e., stream power erosion) inhibits ridge jump events and the formation of microcontinents. The ridge jump event and overall evolution in our numerical models is consistent with the shift from the Mascarene Ridge to the Carlsberg Ridge that determined the formation of the Seychelles microcontinent. We therefore speculate that hillslope erosion, rather than fluvial erosion, was predominant during the formation of the Seychelles, a possible indication of overall dry local climate conditions.

The Longmenshan structural belt on the eastern edge of the Tibetan Plateau experienced the impactful Mw7.9 2008 Wenchuan Earthquake, causing a 350 km surface rupture. Traditional models attribute this to the Beichuan and Pengguan faults, but our research reveals a complex fault system at the northern end, with inconsistencies in surface rupture, aftershock distribution, and focal mechanisms. We integrate shallow geology, active source seismic reflection, and magnetotelluric profiling to establish a deep structural model for the northern end of the Longmenshan structural belt. This area exhibits dominant reverse thrust nappe tectonics, and analyzing the tectonic evolution history provides insights into deformation propagation from the orogenic belt toward the Sichuan Basin. Focal mechanism analysis and relocated aftershock data reveals two distinct types of seismogenic structures in the northern end of the Longmenshan structural belt. In the middle to northern segments, the reverse fault type is attributed to reactivated pre-existing faults. Conversely, at the northern end, the strike-slip fault type originates from high-angle co-seismic rupture cutting through pre-existing reverse faults. This study enhances our understanding of fault complexity and seismic mechanisms in the northeastern Longmenshan structural belt, providing new insights into regional tectonics.

Geochemistry of the fault gouge record information on fault behaviors and environmental conditions. We investigated variations in the mineralogical and geochemical compositions of the fault gouge sampled from the margin zone (MZ) to the slip central zone (CZ) of the fault gouge in the Beichuan-Yingxiu surface rupture zone of the Wenchuan Earthquake.Results show that the clay minerals contents increase from the MZ to CZ, and the quartz and plagioclase contents slight decrease. An increasing enrichment in Al₂O₃, Fe₂O₃, and K₂O are observed toward the CZ; the decomposition of quartz and plagioclase, as well as the depletion of SiO₂, CaO, Na₂O, and P₂O₅ suggest that the alkaline-earth elements are carried away by the fluids. It can be explained that the stronger coseismic actions in the CZ allow more clay minerals to form, decompose quartz and plagioclase, and alter plagioclase to chlorite. The mass loss in the CZ is larger than that in MZ, which is maybe due to the more concentrated stress in the strongly deformed CZ, however other causes will not be excluded.

On December 18, 2023, a Mw6.1 earthquake struck Jishishan County, Gansu Province, China, marking the most significant earthquake in the northeastern edge of the Tibetan Plateau since 2000. Given its proximate to the Loess Plateau, which is extremely susceptible to geohazards, this earthquake raises awareness about the seismic hazard of several mega-cities such as Xi'an in Northwest China. In this paper, we inferred that the rupture occurred on an east-dipping backthrust, resulting from the regional E-W contraction tectonic setting. Our dynamic model through teleseismic waves and static model through radar displacement measurements together reveal a unilateral, along-strike rupture, encountering a slip barrier at one side of the main slip patch causing a cluster of aftershocks. We also identified a high-dip structure, which is an early-stage backthrust fault whose dip becomes increasingly high due to regional compressional tectonism. Apart from the loaded fault segments, particularly on the fault linkage, which necessitate continuous examination, a detailed seismic hazard assessment of the west Qinling and Daotanghe-Linxia fault system identifies a seismic gap between Weiyuan and Dingxi with the potential for a Mw7.5 earthquake. Collectively, these findings provide valuable insights into the seismic behavior of the seismogenic fault as well as guidance on hazard mitigation in its surrounding fault systems.

To tackle the difficulties of the point prediction in quantifying the reliability of landslide displacement prediction, a data-driven combination-interval prediction method (CIPM) based on copula and variational-mode-decomposition associated with kernel-based-extreme-learning-machine optimized by the whale optimization algorithm (VMD-WOA-KELM) is proposed in this paper. Firstly, the displacement is decomposed by VMD to three IMF components and a residual component of different fluctuation characteristics. The key impact factors of each IMF component are selected according to Copula model, and the corresponding WOA-KELM is established to conduct point prediction. Subsequently, the parametric method (PM) and non-parametric method (NPM) are used to estimate the prediction error probability density distribution (PDF) of each component, whose prediction interval (PI) under the 95% confidence level is also obtained. By means of the differential evolution algorithm (DE), a weighted combination model based on the PIs is built to construct the combination-interval (CI). Finally, the CIs of each component are added to generate the total PI. A comparative case study shows that the CIPM performs better in constructing landslide displacement PI with high performance.

An effective warning system for flash floods along the upper River des Peres, a small urban stream in eastern Missouri, USA, is based on three enterprise-level, automated rain gauges. Because floods in this 25 km² basin develop rapidly and are commonly caused by small but intense thunderstorm cells, these rain gauges were necessarily deployed within the watershed, and immediate telemetry and processing of rainfall delivered in 5-minute intervals is required. Available data show that damaging floods in this area occur only 30 min to 3 h following the delivery of 38 mm of rainfall or more in a single hour. Water levels along this stream can rise more than 3 m/h. Since full deployment in Nov. 2021, our system has successfully predicted 3 significant floods with one false positive.

This study describes the use of the weighted multiplicative algebraic reconstruction technique (WMART) to obtain vertical ozone profiles from limb observations performed by the scanning imaging absorption spectrometer for atmospheric chartography (SCIAMACHY). This technique is based on SaskMART (the combination of the multiplicative algebraic reconstruction technique and SaskTRAN radiative transfer model), which was originally developed for optical spectrometer and infrared imaging system (OSIRIS) data. One of the objectives of this study was to obtain consistent ozone profiles from the two satellites. In this study, the WMART algorithm is combined with a radiative transfer model (SCIATRAN), as well as a set of measurement vectors comprising five Hartley pairing vectors (HPVs) and one Chappuis triplet vector (CTV), to retrieve ozone profiles in the altitude range of 10–69 km. Considering that the weighting factors in WMART have a significant effect on the retrievals, we propose a novel approach to calculate the pair/triplet weighting factors using wavelength weighting functions. The results of the application of the proposed ozone retrieval scheme are compared with the SCIAMACHY v3.5 ozone product by University of Bremen and validated against profiles derived from other passive satellite observations or measured by ozonesondes. Between 18 and 55 km, the retrieved ozone profiles typically agree with data from the SCIAMACHY ozone product within 5% for tropics and middle latitudes, whereas a negative deviation exists between 35 and 50 km for northern high latitudes, with a deviation of less than 10% above 50 km. Comparison of the retrieved profiles with microwave limb sounder (MLS) v5.0 indicates that the difference is within ±5% between 18 and 55 km, and an agreement within 10% is achieved in other altitudes for tropics and middle latitudes. Comparison of the retrieved profiles with OSIRIS v7.1 indicates that the average deviation is within ±5% between 20 and 59 km, and difference of approximately 10% is achieved below 20 km. Compared with ozonesondes data, a general validity of the retrievals is no more than 5% between 15 and 30 km.